TW201023677A - White organic light emitting device and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a white organic light emitting device and a method for manufacturing the same, in which a hole transport layer is made to have an energy level higher than an energy level of an excited state of a phosphorescent light emitting layer adjacent thereto for enhancing light emitting efficiency of the hole transport layer without an additional exciton blocking layer, and a dopant content in the phosphorescent light emitting layer is adjusted for preventing color shift from taking place. The white organic light emitting device includes an anode and a cathode placed on a substrate opposite to each other, a charge generation layer formed between the anode and the cathode, a first stack of a first hole transport layer, a first light emitting layer for emitting a blue light, and a first electron transport layer between the anode and the charge generation layer, and a second stack of a second hole transport layer, a second light emitting layer having a host doped with phosphorescence red and green together, and a second electron transport layer between the charge generation layer and the cathode, wherein the second hole transport layer has an energy level set higher than a triplet excited state energy level of the second light emitting layer.

Description

201023677 VI. Description of the Invention: [Technical Field] The present invention relates to an organic light-emitting device, particularly a white organic light-emitting device and a method of fabricating the same, in which the energy transfer layer of the hole transport layer is phosphorescent to the adjacent hole transport layer The excited layer of the luminescent layer has a high energy level for enhancing the luminous efficiency of the hole transport layer, and does not require an additional exciton blocking layer, and the doping content in the luminescent layer Adjusted to avoid color shift (c〇1〇r shift) 〇 [Prior Art] At present, the 'information-oriented era has come completely'. The display field that visually presents electrical information signals has been rapidly developed, and has been developed to meet this development. Various flat display devices having excellent characteristics of light weight and low power consumption are rapidly replacing the current cathode ray tube CRT. As a specific example of the flat display device, there are a liquid crystal display device LCD, a plasma display device PDP, a field emission display device FED, and an organic light-emitting device 〇LEIh in a flat display device, because the organic light-emitting device 〇LED does not require a separate light source, and is easy. The device is compact and can clearly display color and is therefore considered a competitive application. The organic light-emitting device OLED requires an organic light-emitting layer, which is formed in the prior art by depositing a shadow mask. However, if the shadow mask is large, this shadow mask is recessed due to gravity, and 201023677 is difficult to use, and defects occur in the formation of the organic light-emitting layer, so other methods are required. White organic light-emitting devices are one of many methods suggested for replacing shadow masks. A white organic light-emitting device will now be described. The white organic light-emitting device comprises a plurality of layers between the deposited anode and the cathode, and no mask is formed during the formation of the light-emitting diode, wherein the organic film containing the organic light-emitting layer is continuously deposited in a vacuum using materials different from each other. White organic light-emitting devices have many applications, such as a thin light source, a backlight unit in a liquid crystal display device, or a full color display device using a color filter. The white organic light-emitting device comprises a plurality of light-emitting layers, which respectively apply different colors to each other by applying dopants of different colors to the light-emitting layer. However, due to the nature of the dopant itself, the composition of the dopant contained in the luminescent layer is limited, and because the mixture of luminescent layers focuses on producing white light for white light wavelength regions outside the red, green and blue wavelength regions. The white wavelength characteristic with uniform peaks, when the white organic light-emitting device includes a color filter, the color reproduction ratio is deteriorated. Further, since the materials of the dopants are different from each other, if the white organic light-emitting device is continuously used, a color shift occurs. In addition, since the energy transfer layer and the light-emitting layer have similar energy levels at their interfaces, triplet excitons migrate through the interface to the hole transport layer, and the luminous efficiency of the excited state is lowered if an exciton blocking layer is provided. EBL to avoid this, 201023677 is driving the rise? The process steps are increased and the life is shortened, which imposes many obstacles for the white organic light-emitting device that produces the best efficiency. SUMMARY OF THE INVENTION Accordingly, the present invention provides a white organic light-emitting device and a method of fabricating the same. The object of the present invention is to provide a white organic light-emitting device and a method for fabricating the same, wherein the energy level of the hole transport layer is higher than that of the scale light-emitting layer adjacent to the hole transport layer to enhance (4) the transport layer The luminous efficiency does not require an additional exciton blocking layer, and the lining of the luminescent layer is to avoid color shift. Other advantages, objects, and advantages of the present invention will be described in part in the following, and other advantages, objects, and advantages of the present invention will be apparent to those skilled in the art Partially understood or can be derived from the practice of the invention. The object and other advantages of the invention will be realized and attained by the <RTIgt; In order to achieve the objects and other advantages of the present invention, the present invention is embodied and described in detail. A white organic light-emitting device of the present invention comprises: an anode and a cathode disposed opposite each other on a substrate; and a charge generating layer formed on Between the anode and the cathode; a first stacked layer between the anode and the charge generating layer, comprising a first hole transport layer, a first light emitting layer for emitting blue light and a first electron transport layer; and a second stacked layer, located at the charge Between the generation layer and the cathode, comprising a second hole transport layer, a second luminescent layer comprising a body doped with phosphorescent red and green dopants, and 7 201023677 wherein the first hole transport layer comprises an energy level It is set to be higher than the three-state excited state energy level of the second light-emitting layer. The excited state energy level is 0.01. The second transport layer contains an energy level of 〇4 electron volts than the second light-emitting layer. For example, the second hole transport ride is formed by a compound containing an asymmetric structure as shown by the following chemical formula. Chemical formula 1

Wherein R1 is selected from a substituted or unsubstituted aryl or heterocyclic group. In detail, R1 is selected from one of substituted or unsubstituted stupid, shout, tea, and taste. The main system of the first light-emitting layer is selected from a plurality of materials having a high energy transfer ratio to the green light dopant. The red thread is selected from the group having a high energy transfer ratio from the green light dopant and has a _ A plurality of materials of similar lifetime such that even if the time passes, the brightness of the entire wavelength is lowered to the same level, there is no hue change, and thus it is suitable for displaying white light. In another aspect of the invention, a method of fabricating a white organic light-emitting device includes the steps of: forming an anode on a substrate; transmitting a first hole transport layer through a continuous stack, a first light-emitting layer for emitting blue light, and a first electron transport layer Forming a first stacked layer on the substrate including the anode; forming a charge generating layer on the first stacked layer; continuously stacking the second hole transport layer through the 201023677, comprising the phosphorescent red and green dopant doped together a first luminescent layer and a second electron transporting layer on the charge generating layer to form a second stacked layer; and a cathode formed on the second stacked layer, wherein the second hole transport layer includes an energy level 'set to The three-state excited state energy level is higher than the second light-emitting layer. It is to be understood that the foregoing general description of the invention, [Embodiment] Specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The same reference numbers are used in the drawings to refer to the same or like parts. Fig. 1 is a schematic cross-sectional view showing a white organic light-emitting device according to a preferred embodiment of the present invention. Please refer to "FIG. 1", the white organic light-emitting device comprises: an anode 101 and a cathode 140 opposite to each other on the substrate 8 (8); a first stacked layer 210 between the anode 101 and the cathode 140; a charge generating layer 120 and a second stack Layer 220. The anode 101 is formed of a transparent electrode such as Indium Tin Oxide (ITO), and the cathode 140 is formed of a reflective material such as aluminum. Due to the light rays respectively emitted by the first stacked layer 210 and the second stacked layer 220 arranged in the above manner, the image is transmitted to the bottom side of the drawing. The first stacked layer 210 includes a first hole transfer layer (HIL) 103, a first hole transport layer (HTL) 105, a first light emitting layer 110, a first electron transport layer (ETL) 9 201023677 111, and a first electron injection An interlayer (EIL) 113 is continuously stacked between the upper side of the anode 1〇1 and the charge generating layer 120, and the second stacked layer 220 includes the second hole transferring layer 123, the second hole transporting layer 125, and the second light emitting layer 13〇 The second electron transport layer 133 and the second electron injection layer 135 are continuously stacked between the charge generating layer 12A and the cathode 14A. The first light-emitting layer 110 is a light-emitting layer having a blue light body, and includes a dopant having a blue fluorescent component or a phosphorescent component, and the second light-emitting layer 13 is a single light-emitting layer containing a main body. Light green light and dish light red light change. In this example, when the white light organic light-emitting device is driven, the mixing effect of the light emitted by the first light-emitting layer 11 and the second light-emitting layer 130 can produce white. In this case, the second hole transport layer 125 is set to have an energy level souther than the energy level of the excited state of the dimorphic excitons of the second light-emitting layer 13A. In this example, the second hole transport layer 125 is set to have an energy level higher than the energy level of the exciton of the three-state excitons of the second light-emitting layer 130 by 0.01 to 0.4 volts. In this case, since the energy level of the second hole transport layer 125 is higher than the energy level of the second light-emitting layer no, the tri-state excitons of the second light-emitting layer 130 can be prevented from being transferred to the second hole transport layer 125, thereby The luminous efficiency is lowered. That is to say, in this case, the second hole transport layer 25 is used to transfer the holes from the first light-emitting layer 130 and serve as an exciton-resisting layer, which is a unique function of the second light-emitting layer, and the exciton blocking layer is used. To prevent the three-state excitons from reaching. A method of manufacturing a white organic light-emitting device according to a preferred embodiment of the present invention will be described with reference to "Fig. 1". Please refer to "Fig. 1". In the method of manufacturing a white organic light-emitting device, an anode 201023677 is formed on a substrate 100. Then, the first hole transfer layer 103, the first hole transport layer 105, the first light emitting layer 110 for emitting blue, the first electron transport layer 111, and the first electron injection layer 113 are continuously stacked on the anode 101. On the substrate, a first stacked layer 210 is formed. Then, the charge generating layer 120 is formed on the first stacked layer 210. Then, the second hole transfer layer 123, the second hole transport layer 125, the second light-emitting layer 130 including the one body of the doped phosphorescent green light and the phosphorescent red light dopant, the second electron transport layer 133, and the first The two electron injection layers 135 are successively stacked on the charge generation layer 120 to form a second stacked layer 220. Then, a cathode 140 is formed on the second stacked layer 220. In this case, the tri-state energy level of the second hole transport layer 125 is set higher than the energy level of the excited state of the second light-emitting layer 130. The energy transfer mechanism of the white organic light-emitting device of the present invention will now be described. Fig. 2A and Fig. 2B are schematic views showing the energy shifts of the respective layers of the second stacked layer of the white organic light-emitting device of the present invention and the comparative structure, respectively. The "Fig. 2A" shows the energy level of the second hole transport layer 125 which is the same as the second stack layer of the "Fig. 1", and the excited state energy level of the triplet excitons of the second light emitting layer 130. The high-level diagram, shown in Figure 2B, is a structural diagram in which a three-state barrier layer (TBL) is added. When the light-emitting layer 23 is adjacent to the adjacent hole transport layer 225, When the excited state energy level of the triplet excitons of the light-emitting layer 230 is similar, the two-state hindered layer is used to prevent excitons from being introduced into the hole transport layer from the light-emitting layer. 201023677 is the same as the structure of the present invention. In the "Fig. 2B", the electron transport layer 233 and the electron injection layer 235 are formed between the light-emitting layer 230 and the cathode. Herein, the "201B" also includes an anode 201 and a cathode 240. - In the "Fig. 2A", the first stacked layer and the charge generating layer CGL120 are omitted. "3A", "3B" and "3C" are schematic diagrams showing the energy transfer mechanism and the energy transfer mechanism of the comparative structure of the second stacked layer of the white organic light-emitting device of the present invention. © "Fig. 3A" is a structural example of the second stacked layer of the present invention corresponding to "Fig. 2A", and "Fig. 3B" shows the excited energy level of the light emitting layer and the adjacent light emitting layer. The energy level of the hole transport layer is similar, and the "3C figure" is the energy mechanism between the light-emitting layer and the hole transport layer in the structure example corresponding to "2A". Please refer to "3A", the second luminescent layer is composed of phosphorescent host material 13 〇 &amp;

a layer comprising a photo-filled green dopant (referred to as a phosphorescent green photosensitizer) 13〇b Q and a filled red dopant 13〇c, wherein if the second luminescent layer passes through the _ supply current The stimulated '4 light body material is first excited, the singlet exciton 8 tri-state exciton τι and the disc-light green-doped hidden light red light filament 13Qe singlet exciton and tri-state excitons T1 Sg, Tg, Sr, and Tr are continuously excited to emit a mixture of green and red light. In this case, since the energy level of the second hole transport layer 125 is higher than that of the single-mode and three-state excitons of the disk-optic host material 130a, the single-state excimer 12 201023677 and the three-state excitons of the scale light host material cannot be reached. The second transfer layer 125 is retained in the light-emitting layer to help couple the holes and electrons, thereby enhancing luminous efficiency. In this example, the third-state energy level of the second hole transport layer 125 is higher than that of the triplet excitons of the phosphorescent host material 130a of the light-emitting layer, and has good hole transport characteristics and is set to have a second light-emitting layer. The energy level of the three-state excited state energy level is higher than the energy level of 1 to 〇4 electron volts. For example, the second hole transport layer 125 is formed of a material of an asymmetric structure shown by the following chemical formula. Chemical formula 1

Wherein R1 is selected from a substituted or unsubstituted aryl group or a heterocyclic group. In detail, R1 may be selected from a substituted or unsubstituted phenyl group, a pyridine, a naphthalene, a qUin〇iine, and a carbaz〇ie. Although "Fig. 2B" indicates that the energy level of the hole transport layer 225 is higher than the excited state energy level of the light-emitting layer, when the light-emitting layer of the light-emitting body material 23〇a, phosphorescent green light dopant (phosphorescent green photosensitizer) When 230b is combined with the phosphorescent red dopant 230c, this energy level represents the average energy level. As shown in "3B" and "3C", if the energy level of each material is observed, it can be seen that the excited state energy level of the phosphorescent host material 23a is higher than that of the hole transport layer 225. In this example, it is understood that in "Picture 3B", the singlet excitons and the tri-state excitons of the phosphorescent host material 230a are transferred to the hole transport layer 225, and in this example of 13 201023677, the exciton for illuminating After the constituent escapes to the hole transport layer, the exciton component cannot return to the light-emitting layer again. Therefore, as time passes, the luminous efficiency becomes lower and lower. In order to prevent the singlet excitons and the triplet excitons shown in "Fig. 3B" from being injected into the hole injection layer 325' "3C", the tristate barrier layer 227 is provided in the light emitting layer 23 and the hole transmission. Between the layers 225, it is used to prevent excitons from being injected into the hole transport layer 225 from the light-emitting layer 23A. However, in the example of "3C", due to the tri-state resistive layer 227, although excitons can be avoided from escaping to the hole transport layer 225, providing an additional layer adds the step 'in the interface of the light-emitting layer 230. Providing a layer of material for the person increases the driving voltage. It can be seen that the white organic light-emitting device of the present invention including the structure shown in "FIG. 3A" has the first hole transport layer 125', and the energy level of the second hole transport layer 125 is higher than that of the light-emitting layer, so the white of the present invention Organic light-emitting devices are advantageous in terms of luminous efficiency, saving process cost, avoiding increased power consumption, and longevity. Fig. 4 is not a graph showing the wavelength characteristics of red, green and blue light when the red, green and blue light pushers are added to the main material. Please refer to "Fig. 4", which shows the intensity versus wavelength pattern when blue, green, and red dopants are added to the host material from left to right. As can be seen from the graph, the intensity of the red wavelength is low. In the white organic light-emitting device of the present invention, the green light dopant is mixed with the red light dopant as the second light-emitting layer, such that the green light dopant causes an excited state to emit green light, because green light The singlet and triplet transfer energy of 201023677 is emitted to the red light dopant material, thereby increasing the luminous efficiency, which is less than the introduction of the early red light doping, and the luminous efficiency of the color is increased when the red-light green dopant is mixed. Table 1 below shows the driving relocation and brightness of the light. This kind of real money, when driving the power for each color, Wei Lin's financial office branches 3 6 , 3 9 and 4.8 volt range 'measure brightness, quantum efficiency qe and sink coordinate system. , Table 1

Figure 5 is a wavelength characteristic diagram when the content of the red and green dopants is increased to the second phosphor layer of the white organic light-emitting device of the present invention. . e "Fig. 5" shows a graph showing the luminous efficiency of the second stacked layer when the content of the red light dopant is fixed at 〇4% and the content of the green light dopant is changed from 5% to 2% by weight based on the fixed amount of ruthenium. In this example, as shown in Table 2, the luminance, quantum efficiency, and CIE coordinate system were measured while the driving voltage was maintained in the same range of almost 3.6 to 3.7 volts. Please refer to "5th 囷" and Table 2, it can be seen that in the case where the green light dopant content is higher than 15%, the red light luminescence efficiency is higher if the green and red intensity are compared. In this example, 'as mentioned above, because the singlet and tri-state exciton transfer energy of green light to red dopants', the introduction of green light dopants not only contributes to green light emission, but also contributes to red light. Emission efficiency. Form 2 15 201023677

Structure Volt (V) Cd.AG(B%)»R(CL4%) 3.6 30*0 G[10%]+RP&gt;&lt;%] G[15%]+R(〇4%] 3.7 3j6 32JB 27J8 3.7 31 JO

Im-W QE|:,:) Cd?m2 ClEx-ClEy 26.3 2Θ.0 13.5% 16.3% 299B 3278 0.477 QJB07 0.504 0A7B 24.1 264 16.6% 18.9% 2776 3099 0J665 0J572 (M19 0Λ20 Based on these tests, in the following test When the content of the green light dopant is less than 10%, these examples are used to make the luminous efficiency of green light and red light uniform. "Fig. 6" is shown in the green and red light dopants being added. The pattern in which the wavelength characteristics vary with the application of the exciton blocking layer and the red dopant content in the example of the light-emitting layer of the second stacked layer of the white organic light-emitting device of the present invention. "Figure 6" shows the tri-state exciton The application variation of the content of the barrier layer TBL and the red light dopant is 0.1%, 0.2%, and 0.4%, and the wavelength versus intensity pattern is fixed when the content of the green light dopant in the second stacked layer is fixed to 10% (red) +Green light launch). Table 3

Cn〇%^R|0.1%) 6(1Q%HR2L2%1 S(1Q%)+R ©Γ1〇%)+ΙΗ〇, 4%) TBLQ(1〇%WMQjWfc)

________ BSSBESDIBDQIES^HESI 3.8 44JB 402 1U% 4483 i 0.411 : 0j662 48Λ 403 17Λ% 4B52 0^418 0jE66 3_4 39:9 363 16jD% 3988 〇A^ 0532 3.6 4Λ£ 397 4% 4650 044» 0^2» 3Λ 3β3 32.1 Λ7Μ 3652 ΟΛΟΙ 6^82 3.8 »3 — 311 hot aiaa oioe 047ft Please refer to Figure 6 and Table 3. It can be noted that the higher the red dopant content, the greater the intensity of the red wavelength, and if When a tri-state barrier is applied, the intensity of green light emission is higher. The best example is the intensity of light having the same or similar level of green and red. It can be noted that green and red have similar levels of luminescence intensity when about 0.2% of the red dopant is introduced. Based on the above test, it was judged that the contents of red and green in the second stacked layer were set to 0.2% and 1%. The problem of other dopants of the white organic light-emitting device is also described. 201023677 Fig. 7 is a view showing the light-emitting characteristics of the phosphorescent light-emitting layers in which the green light and the orange light dopant are respectively added to the white organic light-emitting device having two stacked layers. "Picture 7" is a characteristic graph of the white organic light-emitting device shown on the gig page of the 39th volume of the SID Journal of the 2008 International Information Display and Display Seminar. The figure shows that the first-stack layer contains a blue light-emitting layer and the second The stack includes examples of primary and green and orange dopants, wherein the curve indicated by · indicates an example of using a dark blue material in the first stacked layer, and the other indicated by ▲ indicates the first stacked layer. An example of using a light blue material. It can be seen that when a dark blue material is used, the wavelength of blue light is stronger than the wavelength of other colors. However, it is understood that regardless of whether or not a blue light-emitting material having a certain light-emitting level is used in the first stacked layer, a broad light emission occurs in each wavelength band, and the light-emitting efficiency is poor in a red light wavelength of 610 nm to 700 nm. That is to say, when the color filter is applied to the white organic light-emitting device, since the red, green, and blue wavelengths can be seen to exhibit significantly different peaks, the color reproduction ratio is rather poor in the red wavelength, and red and green are Poor sensitivity to blue. It can be understood that the problem of the structure shown in "Fig. 7" lies in the green light and the orange light dopant used in the second build-up layer. In the present invention, the orange light in the second stacked layer Replaced by red dopants. "Fig. 8" shows a pattern of brightness characteristics of the following example when the green or red dopant is added to the second light-emitting layer of the second stacked layer of the white organic light-emitting device. Examples of low energy levels, examples of providing exciton blocking layers, 17 201023677 and examples of the energy level of the energy transfer layer of the hole transport layer compared to the three states of the phosphorescent light emitting layer. Fig. 8 shows a test example in which the second light-emitting layer is formed of a host material and the host material is respectively increased by 0.2% of a red light dopant and 10% of a green light dopant. That is to say, 'continuously upward from the lowest side of the curve, the curve of "Fig. 8" represents three examples, respectively, the energy level of the second hole transport layer adjacent to the second light-emitting layer is set to be stimulated with the second light-emitting layer. An example of a similar level of energy level is the example in which the tri-state barrier layer is added to the interface between the second light-emitting layer and the second hole transport layer, and the material of the second hole transport layer is changed by β to cause the second hole to be transferred. An example in which the energy level of the layer is higher than the excited state energy of the second luminescent layer. Please refer to "Fig. 8" and Table 4 below. It can be noted that if a general hole transmission layer is provided, although the driving voltage is 3.4 volts, 'not very high, but the number of illuminations is 39.9 Cd/A, 36.8 ww, and willow. The crime is -2 and the luminous efficiency is ΐό 〇%, which is low. If the tri-state resistive layer is added to the interface between the general hole transport layer and the light-emitting layer, ❹ compared with the foregoing example, although the number of light-emitting is 45.5 Cd/A, 妁; 7 lm/W, 455 〇 Cd/m2 'and The luminous efficiency is 4% for the team, which shows an increase. As the driving voltage rises to 3.6 volts, the power consumption is expected to increase. In contrast, in the example of providing the second hole transport layer, the energy level of the second light-emitting layer of the white organic light-emitting device of the present invention is higher than the electron volts, and the driving cost is 3.2 volts. 3.3 volts and 3.0 volts, all 18 201023677 is lower than the above two examples' and the luminous efficiencies are 20.6%, 19.6%, 21.3%, both perform higher. In all instances, the CIE coordinate system exhibits coordinates that are similar to each other. Form 4

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"Fig. 9" indicates that when the first and second stacked layers are supplied to the white organic light-emitting device, the hole transport layer of the second transfer layer contains different energy levels or an exciton blocking layer is provided at the interface of the scale light-emitting layer. A graph of luminance characteristics versus wavelength in an example. "Fig. 9" shows the wavelength intensity when the first and second stacked layers are supplied to the white organic light-emitting device, indicating that the blue light-emitting layer is added to the above three examples described in "Fig. 8". The state of the first stacked layer, three examples, that is, the energy level of the second hole transport layer adjacent to the second light-emitting layer is set to be similar to the excited energy level of the second light-emitting layer, and the three-state barrier layer is An example of increasing the interface to the second light-emitting layer and the second hole transport layer, and the material of the second hole transport layer is changed such that the energy level of the first hole transport layer is higher than the excited state of the second light-emitting layer An example of a step height. Please refer to FIG. 9 for an example in which the first and second stacked layers are the same as the white organic light-emitting device of the present invention, and the energy level of the second hole transport layer is higher than the excited state energy level of the second light-emitting layer. It can be noted that the blue, green, and red wavelengths respectively include consistent intensity, sharp peaks in color, and similar peaks. Please refer to Table 5 below. It can also be noted that the white organic light-emitting device 201023677 of the present invention contains a lower driving voltage (6.4 volts) than other structures, and the luminous efficiency is increased to 29.3%. In this example, the luminous intensity was 7 ed/A, 28 〇 , and w797 Cd/m 2 . In the CIE coordinate system, CI£x is 〇 366 and CIEy is 〇 4〇2. Form 5

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The "Fig. 10" is not a graph in which the brightness of the white organic hairline of the present invention changes with respect to the wavelength as a function of aging. Fig. 10 shows an example of the initial state intensity of each wavelength from the upper side of the white organic hairline to the bottom, an example of aging of about 30%, and an example of aging of about 50%. Please refer to Figure 10 and Table 6 below. The initial state, 3〇% aging and 50% aging indicate that the intensity of the color does not decrease, but the intensity in each color gradually decreases according to the consistent level. This means that even though time passes, the intensity as a whole

reduce. For example, if only the red wavelength is severely aged, if it is attempted to produce white light, the light emission efficiency will be significantly different for the light other than red light, that is, the luminous efficiency of green light and blue light. Table 6 ~~I 214 | 3〇JS 1 ηΐ\ __ Atiru. a ^t»rL- 75

7J BBS 47T5 24.6% 15.5% Gas 3 1Z2% mo CiE &lt; CIE &lt; ormo ••338 -aM7 •33B -0UK7 ^i|!-l£y ί:|Ε u Ju' CiEv' 翳圜蹋费豳gaBSHsa with (4) • αοοι 4J007 Therefore, the main system of the first light-emitting layer is selected from a material having a high energy transfer ratio to the green light dopant, and the red light dopant is selected from the green light dopant having a high energy transfer 20 201023677 The white organic light-emitting device of the present invention is suitable for producing white materials such that the brightness of all wavelengths is reduced by the same level 'no color generalization' even if the time lapses. That is to say, the distribution _ color ray = the life of the debris _, so that the dopant of the sample, from (10) time lapse, only the overall intensity of the light is reduced, when the wavelength is reduced to _ can detect white light 'Thus avoiding the color shift that occurs in the white organic light-emitting devices of the two stacked layers of the prior art. As described above, the white organic light-emitting device of the present invention and the method of manufacturing the same have the following advantages. In a white organic light-emitting device having two stacking layers, each comprises a blue light-emitting layer and a thief-colored and red-aged light-emitting layer formed between the anode and the cathode, and the energy of the hole transport layer adjacent to the green and red mixed light-emitting layer The order is set to be 0.01 to 0.4 eV higher than the excited state energy level to prevent the excited excitons from being introduced into the hole transport layer. Therefore, the hole transport layer completes the hole transfer function and acts as an exciton (single state and polymorphic) barrier layer, eliminating the exciton blocking layer, and the white organic light-emitting device does not increase the number of processing steps and can reduce power consumption. In addition to this, the singlet excitons and the tri-state exciton portions remaining in the light-emitting layer are used for continuous light emission, so that luminous efficiency can be improved. In addition, when white light is generated, a stacked layer is formed as a light-emitting layer containing a blue light dopant and another stacked layer is included to contain an appropriate amount of a green light and a red light dopant host material, thereby being capable of being red, The green and blue wavelength regions exhibit consistent peaks and different peaks'. When color filters are applied, the color reproduction ratio can be improved. 21 201023677 The use of dopants with similar lifetimes when using different color dopants allows to avoid the wavelength intensities of a certain color, thus avoiding color shift. Although the present invention has been disclosed above in the foregoing embodiments, it is not intended to limit the invention. It is within the scope of the invention to be modified and modified without departing from the spirit and scope of the invention. Please refer to the attached patent application scope for the scope of protection defined by the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing a white organic light-emitting device according to a preferred embodiment of the present invention; FIGS. 2A and 2B are respectively a view of the white organic light-emitting device of the present invention. Schematic diagram of the energy offset of the two stacks and the comparative structure; Figures 3A to 3C show the energy transfer mechanism of the first-stack layer of the white organic light-emitting device of the present invention and the energy transfer mechanism of the comparative structure, respectively. Τ3Ί · circle, Figure 4 is not a pattern of red, green, and blue wavelength characteristics when the red, green, and blue light-changing materials are added to the host material (5) barren material; the figure is green light A graph showing the wavelength characteristics when the content of the green light dopant is changed in the example in which the red light dopant is added to the light-emitting layer of the first stack layer of the white organic light-emitting device of the present invention; In order to change the green light and red light inclusions to the light-emitting layer of the second stacked layer of the white organic light-emitting device of the present invention, the wavelength characteristics vary with the application of the exciton resistance 22 201023677 layer and the red light dopant content. Figure; Figure 7 The figure is a graph of the luminescent properties of the phosphorescent luminescent layer which is respectively added to the green light and the orange light dopant in the white organic light-emitting device having two stacked layers; FIG. 8 is a view when the green light or the red light is mixed When the foreign matter is added to the second light emitting layer of the second stacked layer of the white organic light emitting device, the hole transport layer has an example of a low energy level, an example of providing an exciton blocking layer, and the hole transport layer includes an energy level light emitting light The luminance characteristic pattern of the example of the energy level when the three-state of the layer is excited; FIG. 9 is the hole transport layer of the second transport layer when the first and second stacked layers are provided to the white organic light-emitting device a pattern of luminance characteristics versus wavelength in an example where an interface of different energy levels or exciton blocking layers is provided to the phosphorescent emissive layer; and FIG. 10 is a graph showing the brightness versus wavelength of the white organic light-emitting device of the present invention as a function of aging The graphic of change. [Main component symbol description] 100 ..........................substrate 101 ............... ........... anode 103 ..........................first hole transfer layer 105 .... ......................The first hole transport layer 110 ..................... ..... first light-emitting layer first electron transport layer first electron injection layer 23 113 201023677 120 ..........................charge Generate layer 123 ..........................Second hole transfer layer 125 .............. ............second hole transport layer 130.........................second light-emitting layer 133 ..........................Second electron transport layer 135.................. ........Second Electron Injection Layer 140 ..........................Cathode 210 ........ ..................The first stacking layer © 220 ......................... Second stacked layer 201 .................... anode 225 ................. ......... hole transport layer 230 .......................... luminescent layer 233 ....... ...................Electronic Transport Layer 235 ..........................Electronics Injection layer 240 .......................... cathode © 13〇a .......................... Phosphorescent host material 130b ................ ..........phosphorescent green dopant 130c.........................phosphorescent red dopant 230a ..........................phosphorescent host material · 230b ................... .......phosphorescent green dopant 230c ....................phosphorescent red dopant 24 201023677 325 . ......................... Hole injection layer 227 .................... ...three-state barrier ❹ 25

Claims (1)

201023677 VII. Patent application scope: 1. A white organic light-emitting device comprising: an anode and a cathode disposed opposite each other on a substrate; a charge generating layer formed between the anode and the cathode; a first stack a layer between the anode and the charge generating layer, comprising a first hole transport layer, a first light emitting layer for emitting a blue light, and a first electron transport layer; and a second stacked layer Between the charge generating layer and the cathode, comprising a second hole transport layer, a second luminescent layer comprising one of the main bodies doped with phosphorescent red and green light dopants, and a second electron transport layer, wherein The second hole transport layer includes a white organic light-emitting device, wherein the energy level is set to be one of the third-state excited states of the second light-emitting layer. The second transmission layer includes the energy level higher than the three-state excited state energy level of the second light-emitting layer by ~0.4 eV. 3. The white organic light-emitting device of claim 2, wherein the second hole transport layer is formed of a compound comprising an asymmetric structure as shown by the following chemical formula. Chemical Formula 1 201023677 wherein R1 is selected from a mono- or unsubstituted aryl group or a heterocyclic group. 4. The white organic light-emitting device according to claim 3, wherein the phantom is selected from the group consisting of a substituted or unsubstituted phenyl group, a pyridine, a naphthalene, a quinoline, and a carbazole. one of them. 5. The white organic light-emitting device of claim 1, wherein the main system of the second light-emitting layer is selected from a plurality of materials having a high energy transfer ratio to one of the green light dopants, and the red The light dopant is selected from a plurality of materials having a high energy transfer ratio from one of the green light dopants and having a similar lifetime to the green light dopant. 6. A method of fabricating a white organic light-emitting device, comprising the steps of: forming an anode on a substrate; continuously stacking a first hole transport layer, emitting a blue light-emitting layer, and - The electron transport layer forms a first stacked layer on the substrate including the anode; forms a charge generating layer on the first stacked layer; and continuously stacks the second hole transport layer, including the common mixed scaly light Red and green light lion - the second light emitting layer and the second electron transport layer on the charge generating layer form a second stacked layer; and a cathode is formed on the second stacked layer, wherein The second hole transport layer includes an energy level, which is set to be higher than a tri-state excited state energy level of the second light-emitting layer. The method of manufacturing a white organic light-emitting device according to Item 6, wherein the first transport layer comprises an energy level, which is set to be larger than the three-state excited state of the second light-emitting layer. The energy level is 0.01 to 0.4 eV. 8. The method of producing a white organic hairline according to item 6, wherein the second hole transport layer is formed of a compound having an asymmetric structure represented by the following chemical formula. Chemical formula 1 Wherein R1 is selected from a monosubstituted or unsubstituted aryl group or a heterocyclic group. 9. The method of producing a white organic light-emitting device according to claim 8, wherein R1 is selected from a substituted or unsubstituted phenyl group. Pyridine, naphthalene, quinoline, and carbazole 28